Physical studies of asteroids - XXXIII. The spin rate of M-type asteroidsC.-I. Lagerkvist, I. Belskaya, A. Erikson, V. Schevchenko, S. Mottola, V. Chiorny, P. Magnusson, A. Nathues and J. PiironenAstron. Astrophys. Suppl. Ser., 131 1 (1998) 55-62DOI: https://doi.org/10.1051/aas:1998425